Funny, I always saw sucking hot air into the PS and venting it out the back as the norm. What surprises me, though is that the fans seem on the wrong end (i.e., you don't so much suck hot air out the P/S as push it through the P/S).
I was also greatly suprised to see that the portholes in the front are much less functional that I would have expected. Also lots of places where vent holes in the sheet metal don't match vent holes in the plastics.